In geometry class, the girl to boy ratio is $8$ to $3$. If there are a total of $55$ students, how many boys are there?
A ratio of $8$ girls to $3$ boys means that a set of $11$ students will have $8$ girls and $3$ boys. A class of $55$ students has $5$ sets of $11$ students. Because we know that there are $3$ boys in each set of $11$ students, the class must have $5$ groups of $3$ boys each. There is a total of $15$ boys in geometry class.